The invention relates to a method and arrangement for controlling the brake(s) of a device for transporting people, such as an escalator or a moving sidewalk.
According to presently applicable domestic and foreign safety regulations, escalators and moving sidewalks must be provided with mechanisms that automatically stop them before the speed exceeds, for example, 1.2 times the value of the nominal speed. In the same way, they must be stopped as soon as malfunctions occur in a region of the escalators or the moving sidewalk, for example if a safety switch is activated.
Mechanical brakes, such as block brakes, are frequently used for escalators and moving sidewalks and are applied abruptly in case of a malfunction, given the currently used controls.
One disadvantage with such mechanical brakes is persons standing on the escalator or on the moving sidewalk under some circumstances can fall and hurt themselves as a result of the abrupt application of the brake.
A further disadvantage is that if the brake linings are worn, the braking distance is extended, even if the brake is applied abruptly.
When these functional interruptions occur in a region of the transporting device, conventional solutions apply a full braking operation to stop the motor. However, a full braking operation in some circumstances could cause persons on the device for transporting people to fall down as a result of the abrupt deceleration of the device for transporting people. Thus, what is needed is a method and corresponding arrangement for the controlled braking of a device for transporting people, which nevertheless meets all relevant domestic and foreign safety standards.
It is an object of this invention to provide a method and a device for controlling the brake(s) of a device for transporting people, such as an escalator or a moving sidewalk, which make it possible to maintain for the most part essentially the same braking distance, even if the brake linings are worn, without this resulting in injury to persons.
This object is achieved by a method for controlling the respective brake of a device for transporting people, such as an escalator or a moving sidewalk, by monitoring the control signals from the drive motor and the brake with the aid of several processors, by applying the brake abruptly during functional interruptions in a region of the device for transporting people, by relieving the brake(s) in a defined manner if deceleration values are detected and by subsequently stopping the device for transporting people with the aid of the processors within a predetermined time interval.
The above object is further achieved with a device for controlling the respective brake of a device for transporting people, having at least two processors that monitor each other and are connected via driver elements to the switching elements for the brake.
Further features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings.